Stone tools, Stone quarries, and tracing “spheres of influence” across the Pacific By: John M. Sinton, Dept. of Geology & Geophysics

adze Kaua‘i adze C-159 SiO TiO Al 2 O FeO* MnO MgO CaO Na 2 O K2OK2O P2O5P2O Sum LOI * total Fe as FeO LOI = loss on ignition at 900°C Rock sections viewed through the microscope adze (large adze found in Honolulu Harbor) C-159 (sample collected by G. A. Macdonald from Pu‘u Pāpa‘i, Moloka‘i apatite crystals Chemical analyses of rocks Pu‘u Pāpa‘i, E. Moloka‘i

(pre-contact) Polynesian Stone Tools Figures from Encyclopédie de la Polynésie

Different stones for different uses Vesicular pāhoehoe lava makes a lousy adze, but an excellent grinding or polishing stone Coarse-grained rocks make lousy adzes, but excellent sinkers and lures Glass is best for cutters and scrapers (but hard to find in large pieces) Good Adze Source Rocks 1. Fine-grained, equigranular is ideal need to be able to fabricate and hold a fine edge without breaking 2. Minimum vesicularity ‘a‘ā flow interiors, dikes, many massive alkalic lavas 3. Not very porphyritic (crystals are defects in rock structure) most postshield alkalic rocks are aphyric, so are many shield lavas 4. Fractures previously fractured outcrops save labor columnar jointed lavas and dikes were widely exploited sources unusual cooling of Mauna Kea lava that ponded against ice.

Archeologists use artifacts to make interpretations about “spheres of influence” This map shows some known and suspected interactions based on ethnohistoric sources and documented transfers of artifacts (mainly lithic) These interpretations are largely based on macroscopic appearance or stylistic similarities Weisler, 1998

The Role of Geochemistry and Petrology Any rock can be described in terms of: Texture Mineralogy Chemical Composition Although Polynesians largely selected rocks based on physical properties (texture and fracture characteristics), the best method for “sourcing” artifacts is through the use of quantitative geochemical data. Ideal matches of artifacts to sources The artifact has the same texture, mineralogy and chemical composition within uncertainties to a known source (outcrop, volcano, island) Chemical data can be fully quantitative, allowing for realistic uncertainty estimates to be determined.

Sources of Uncertainty Analytical UncertaintyQuarry Variability Different analytical methods have different inherent “errors” Two critical analytical issues are precision (reproducibility) and accuracy (correctness) How variable is the actual source area? This can only be determined from dedicated investigations of specific quarries Chemical Data for Eiao Adze Quarry Average of 17 analyses ± 1 standard deviation

Known Polynesian Adze Quarries (not including New Zealand) Hawai‘i – 14 Samoa (Tutuila) – 4 Cook Is. – 4 Austral Is. – 3 Pitcairn – 2 Rapa Nui – 5 Marquesas – 4 Society Is. – 5 By far the three biggest (export) quarries are Mauna Kea Tataga matau (Samoa) Eiao (N. Marquesas)

Quarry Types (from a geological perspective) Outcrops: 1.Columnar lavas (Tahiti) 2.Dikes (Tahiti and elsewhere - see also residual dike rock) 3.Massive lava flows (W. Moloka‘i, Kailua, Kaho‘olawe, Haleakalā, Rurutu) 4.Massive flow chilled against ice (Mauna Kea) Residual Deposits 1.Dike boulders in streams on Ra‘iatea 2.Major quarry of dike rocks in alluvial (stream) deposit on Eiao, N. Marquesas Columnar jointed lava, East Maui

Dike Quarry – Papeenoo Valley, Tahiti

Mauna Kea Adze Quarry Glacially chilled hawaiite lava flow

Eiao, N. Marquesas Selective mining of dike rocks in stream deposit

Hawaiian Sources Large squares denote documented quarries; small squares are other sources

Evidence of Interaction 1.Tataga-matau adzes in N. Cook Is. 2.Tataga-matau maybe in Line Is. 3.Eiao throughout Marquesas 4.Eiao on Moorea 5.Eiao on Mangareva (Gambier) 6.Pu‘u Wa‘awa‘a obsidian in Halawa (O‘ahu) 7.Pu‘u Mō‘iwi (Kaho‘olawe) adze on Kaua‘i 8.Mauna Kea adze on O‘ahu 9.Moloka‘i adze on O‘ahu and Kaua‘I 10.Pitcairn obsidian on Henderson atoll Don’t know: - Process of transfer (commercial enterprise, bartar, exchange) - Organizational system for quarries (ownership if any, division of labor) Major interaction within archipelagos; limited interaction between archipelagos

Eiao – An important adze quarry in the Northern Marquesas

Archeological Investigations at Hanamiai, Tahuata B. Rolett, Univ. Hawai‘i, Dept. Anthropology

Evidence for major breakdown in the system of interaction ~1450 A.D.